Rotor blade panels, along with methods of their formation, are provided. The rotor blade panel may include one or more fiber-reinforced outer skins having an inner surface; and, a plurality of reinforcement structures on the inner surface of the one or more fiber-reinforced outer skins, where the reinforcement structure bonds to the one or more fiber-reinforced outer skins as the reinforcement structure is being deposited. The reinforcement structure includes, at least, a first composition and a second composition, with the first composition being different than the second composition.